EP0587923A1 - High-frequency constant-current feeding system - Google Patents
High-frequency constant-current feeding system Download PDFInfo
- Publication number
- EP0587923A1 EP0587923A1 EP92115671A EP92115671A EP0587923A1 EP 0587923 A1 EP0587923 A1 EP 0587923A1 EP 92115671 A EP92115671 A EP 92115671A EP 92115671 A EP92115671 A EP 92115671A EP 0587923 A1 EP0587923 A1 EP 0587923A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- current
- frequency constant
- core
- power supply
- magnetic resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000004804 winding Methods 0.000 claims abstract description 38
- 230000001105 regulatory effect Effects 0.000 claims description 6
- 230000001747 exhibiting effect Effects 0.000 claims description 2
- 239000003990 capacitor Substances 0.000 description 5
- 239000004020 conductor Substances 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/24—Circuit arrangements in which the lamp is fed by high frequency ac, or with separate oscillator frequency
- H05B41/245—Circuit arrangements in which the lamp is fed by high frequency ac, or with separate oscillator frequency for a plurality of lamps
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
- H05B41/2821—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a single-switch converter or a parallel push-pull converter in the final stage
- H05B41/2822—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a single-switch converter or a parallel push-pull converter in the final stage using specially adapted components in the load circuit, e.g. feed-back transformers, piezoelectric transformers; using specially adapted load circuit configurations
Definitions
- the effective cross-sectional area of this portion of the core is reduced so that the overall magnetic resistance of the core increases.
- the lines of magnetic flux diminish so that the value of the current which flows through the secondary winding can be reduced.
- the brightness of the fluorescent lamp 5c can be varied by adjusting the angle through which the movable portion 7 is turned.
- the E-shaped cores 8 of the current transformer 4d vertically relative to each other to change the magnetic gap between them, the brightness of the incandescent lamp 5d can be varied. If the inverter 2 is provided beforehand with means for increasing and decreasing the value of the output current, the power supplied to all of the loads can be regulated uniformly.
Abstract
A high-frequency constant-current feeding system for supplying electric power from a high-frequency constant-current power supply to loads by using current transformers includes a high-frequency constant-current power supply and a plurality of current transformers each having a primary and secondary windings. A load is connected to the secondary winding of each current transformer, and the primary windings of all of the current transformers are serially connected to the high-frequency constant-current power supply.
Description
- This invention relates to a high-frequency constant-current feeding system for supplying electric power from a high-frequency constant-current power supply to a load by using a current transformer.
- In the prior art, commercial and other power supplies usually are of the constant-voltage type. Depending upon the type of load, however, there are occasions where constant-current power supplies are convenient. For example, when the load is a fluorescent lamp, the characteristic is a negative load characteristic, and therefore it is very difficult to vary the brightness of the lamp by increasing or decreasing the discharge voltage. With a constant-current power supply, however, it is simple to achieve a variation in brightness by increasing or decreasing the discharge current, and lamp brightness can be controlled in stable fashion. For this reason, the constant-current power supply is preferred over the constant-voltage power supply. Further, in the case of an incandescent lamp, the filament exhibits a low resistance before the lamp is lit. After a current is passed through the filament to light the lamp, the resistance value thereof attains the steady state once a high temperature has been reached. Accordingly, if an incandescent lamp is lit using a constant-voltage power supply, an excessively large current flows through the filament in a short period of time when the lamp is lit, and therefore the filament sustains considerable fatigue at such time. If the lamp is lit by a constant-current power supply, however, there is no flow of excessive current at lighting of the lamp. This makes it possible to lengthen markedly the service life of the lamp.
- Accordingly, an object of the present invention is to provide a high-frequency constant-current feeding system for supplying electric power from a high-frequency constant-current power supply to a load by using a current transformer.
- According to the present invention, the foregoing object is attained by providing a high-frequency constant-current feeding system which comprises a high-frequency constant-current power supply, and a plurality of current transformers each having a primary winding and a secondary winding; a load being connected to the secondary winding of each current transformer, and the primary windings of all of the current transformers being serially connected to the high-frequency constant-current power supply.
- In another aspect of the present invention, the foregoing object is attained by providing a high-frequency constant-current feeding system which comprises a high-frequency constant-current power supply, and a plurality of current transformers each having a core exhibiting magnetic resistance, means for adjusting the magnetic resistance of the core, and a primary winding and a secondary winding; a load being connected to the secondary winding of each current transformer, and the primary windings of all of the current transformers being serially connected to the high-frequency constant-current power supply.
- Means for adjusting the magnetic resistance of the core includes a movable member provided on a portion of the core, wherein the effective cross-sectional area of the core or the magnetic gap of the core is varied by moving the movable member, thereby adjusting the magnetic resistance of the core.
- Further, the high-frequency constant-current power supply has means for regulating the value of an output current thereof.
- In terms of operation when a load is a fluorescent lamp, the associated current transformer is saturated and almost no current flows through its secondary winding before discharge of the fluorescent lamp is started. After the start of discharge, however, a discharge current, which is decided by the value of the current which flows through the primary winding of the current transformer as well as by the winding ratio, flows through the fluorescent lamp. Stable operation is achieved when the terminal voltage of the secondary winding has fallen to a discharge voltage corresponding to the discharge current of the fluorescent lamp. In a case where the current transformer is provided with means for adjusting the magnetic resistance of its core, the value of the current which flows into the secondary winding can be adjusted. As a result, the brightness of the fluorescent lamp connected to this current transformer can be varied stably without any loss. In addition, the brightnesses of all connected fluorescent lamps can be varied by adjusting the current value using current adjusting means provided on the high-frequency constant-current power supply.
- Furthermore, if the magnetic resistance of the current transformer is adjusted to infinity, the value of the current which flows through the secondary winding becomes zero. As a result, the power supplied to the load connected to this current transformer can be interrupted and means for adjusting the magnetic resistance can be provided with a switch function.
- Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
-
- Fig. 1 is a diagram for describing an embodiment of a high-frequency constant-current feeding system according to the present invention;
- Fig. 2 is a perspective view illustrating one current transformer in the system of Fig. 1; and
- Fig. 3 is a perspective view illustrating another current transformer in the system of Fig. 1.
- A preferred embodiment of a high-frequency constant-current feeding system according to the present invention will be described with reference to Fig. 1.
- As shown in Fig. 1, an
inverter 2 is connected to a commercial power supply 1, aconductor 3 in the form of a loop is connected across the output terminals of theinverter 2, and the primary windings of all of a plurality ofcurrent transformers conductor 3.Fluorescent lamps current transformers incandescent lamp 5d is connected as a load to the secondary winding of thecurrent transformer 4d. Other fluorescent lamps, incandescent lamps, motors, heaters and other loads are connected to other current transformers, which are not shown. - The output of the
inverter 2 is a high-frequency constant current, in which f = 65 kHz and I₀ = 10 A. Each of the current transformers includes an annular core consisting of ferrite, which exhibits an excellent high-frequency characteristic, and having a cross-sectional area of 1 cm², as well as primary and secondary windings wound upon the core. The primary and secondary windings of thecurrent transformer 4a consist of two turns and 36 turns, respectively, and thefluorescent lamp 5a connected to thecurrent transformer 4a is rated at 110 W and is one available on the market. The capacitor Ca of this fluorescent lamp has a capacitance of 0.0023 µF. The primary windings of thecurrent transformers 4b, 4c each consist of one turn, which is obtained merely by passing theconductor 3 through the annular core, and the secondary windings of these current transformers consist of 24 turns each. Thefluorescent lamps current transformer 4d comprises a combination of two E-shaped cores and has a primary winding consisting of one turn, which is obtained by passing theconductor 3 through the annular core, as well as a secondary winding having ten turns. Theincandescent lamp 5d connected to the current transformer is rated at 100 V, 100 W. - The
current transformers 4c and 4d have means for adjusting the magnetic resistance of the core. As illustrated in Fig. 2, the core of the current transformer 4c includes a generally U-shapedmain portion 6 and amovable portion 7 supported on themain portion 6 so as to be capable of being turned. By turning themovable portion 7 while keeping it in contact with themain portion 6, the effective cross-sectional area of contact between the two portions can be increased or decreased to make it possible to adjust the overall magnetic resistance. Further, as shown in Fig. 3, the core of thecurrent transformer 4d comprises twoE-shaped cores 8 which turn about ahinge 9 to increase or decrease the magnetic gap between them, thereby adjusting the magnetic resistance. - The operation of the fluorescent lamps will be described with regard to
fluorescent lamp 5a. - A high-frequency current is passed through the
conductor 3. Before thefluorescent lamp 5a begins to discharge, a currentcurrent transformer 4a through the capacitor Ca, thereby heating the heater of thefluorescent lamp 5a. The impedance of the capacitor Ca at a frequency f of 65 kHz is 520 Ω. Accordingly, the heater of thefluorescent lamp 5a develops a voltage of 290 V and a transition to hot-cathode discharge is made in a short period of time. The characteristic of thefluorescent lamp 5a is such that when discharge starts, the voltage falls to a discharge voltage of 180 V, which corresponds to a discharge current of 0.55 A. When this state has been attained, thefluorescent lamp 5a fires and lights in a stable manner. - A current of Id = 1 A which initially flows through the secondary winding of the
current transformer 4d flows into the filament of theincandescent lamp 5d. During the time that the resistance value of the filament is initially small, thelamp 5d lights darkly. However, as the filament gradually heats up and the resistance value thereof rises, theincandescent lamp 5d grows brighter. The steady state is attained 0.2 ∼ 0.5 sec after the start of current flow. - When the
movable portion 7 of the current transformer 4c is turned in a horizontal plane, as shown in Fig. 2, after thefluorescent lamp 5c has attained the stably lit state, the effective cross-sectional area of this portion of the core is reduced so that the overall magnetic resistance of the core increases. As a result, the lines of magnetic flux diminish so that the value of the current which flows through the secondary winding can be reduced. More specifically, the brightness of thefluorescent lamp 5c can be varied by adjusting the angle through which themovable portion 7 is turned. Similarly, by turning theE-shaped cores 8 of thecurrent transformer 4d vertically relative to each other to change the magnetic gap between them, the brightness of theincandescent lamp 5d can be varied. If theinverter 2 is provided beforehand with means for increasing and decreasing the value of the output current, the power supplied to all of the loads can be regulated uniformly. - It should be noted that the frequency of the output current of the
inverter 2 is not limited to the value mentioned in the above-described embodiment but is capable of being suitably selected over a wide range of 1 ∼ 150 kHz. However, at frequencies below 20 kHz, there is the possibility that audio-frequency noise will be produced, and there is the risk that frequencies in the range of 30 ∼ 37 kHz will cause erroneous operation of remote-control devices for television and the like. Accordingly, a frequency above 40 kHz is desirable. In addition, the current value of the output current, the shape and dimensions of the current transformers, the shape of the movable portion, the numbers of turns of the primary and secondary windings and the number of loads, etc., can all be designed and changed as required. - In accordance with the high-frequency constant-current feeding system according to the present invention, as described above, it is possible to feed current to each of a variety of loads. In particular, when the current feeding system is applied to fluorescent lamps, operation of the lamps can be controlled much more stably in comparison with current feed using a constant-voltage power supply. The appliances can be made small in size since it is unnecessary to provide a lighting stabilizer or lighting inverter for each and every fluorescent lamp. Furthermore, since transient abnormal current or abnormal voltage is not produced, the lifetime of fluorescent lamps and incandescent lamps can be greatly prolonged. By providing means for adjusting the magnetic resistance of the cores of the current transformers, the power supplied to the individual loads can be regulated very easily without loss. If the high-frequency constant-current power supply is provided with means for adjusting the value of the output current, the power supplied to all of the loads can be regulated in a uniform manner.
- As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
Claims (6)
- A high-frequency constant-current feeding system which comprises:
a high-frequency constant-current power supply; and
a plurality of current transformers each having a primary winding and a secondary winding;
a load being connected to the secondary winding of each current transformer, and the primary windings of all of said current transformers being serially connected to said high-frequency constant-current power supply. - The system according to claim 1, wherein said high-frequency constant-current power supply has means for regulating the value of an output current thereof.
- A high-frequency constant-current feeding system which comprises:
a high-frequency constant-current power supply; and
a plurality of current transformers each having a core exhibiting magnetic resistance, means for adjusting the magnetic resistance of the core, and a primary winding and a secondary winding;
a load being connected to the secondary winding of each current transformer, and the primary windings of all of said current transformers being serially connected to said high-frequency constant-current power supply. - The system according to claim 3, wherein said high-frequency constant-current power supply has means for regulating the value of an output current thereof.
- The system according to claim 3, wherein said means for adjusting the magnetic resistance of the core includes a movable member provided on a portion of said core, the effective cross-sectional area of said core being varied by moving said movable member, thereby adjusting the magnetic resistance of said core.
- The system according to claim 3, wherein said means for adjusting the magnetic resistance of the core includes a movable member provided on a portion of said core, the magnetic gap of said core being varied by moving said movable member, thereby adjusting the magnetic resistance of said core.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP92115671A EP0587923A1 (en) | 1992-09-14 | 1992-09-14 | High-frequency constant-current feeding system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP92115671A EP0587923A1 (en) | 1992-09-14 | 1992-09-14 | High-frequency constant-current feeding system |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0587923A1 true EP0587923A1 (en) | 1994-03-23 |
Family
ID=8210000
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP92115671A Withdrawn EP0587923A1 (en) | 1992-09-14 | 1992-09-14 | High-frequency constant-current feeding system |
Country Status (1)
Country | Link |
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EP (1) | EP0587923A1 (en) |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998033256A1 (en) * | 1997-01-28 | 1998-07-30 | Tunewell Technology Limited | An a.c. current distribution system |
EP0880873A1 (en) * | 1995-10-24 | 1998-12-02 | Auckland UniServices Limited | Inductively powered lighting |
FR2815809A1 (en) * | 2000-10-23 | 2002-04-26 | Augier S A | Warning lamp system with low energy consumption, uses main transformer driven by current source supplying series connected lamp units, each lamp unit having fluorescent tube supplied through transformer |
WO2002035891A2 (en) * | 2000-10-25 | 2002-05-02 | Raymarine Limited | Fluorescent lamp driver circuit |
EP1397028A1 (en) * | 2002-09-06 | 2004-03-10 | Minebea Co., Ltd. | Ballast for a plurality of discharge lamps |
WO2004105207A1 (en) * | 2003-05-26 | 2004-12-02 | Auckland Uniservices Limited | Parallel-tuned pick-up system with multiple voltage outputs |
EP1671521A2 (en) * | 2003-10-06 | 2006-06-21 | Microsemi Corporation | A current sharing scheme and device for multiple ccf lamp operation |
EP1730617A2 (en) * | 2004-03-12 | 2006-12-13 | Juno Manufacturing, Inc. | Constant current class 3 lighting system |
US7646152B2 (en) | 2004-04-01 | 2010-01-12 | Microsemi Corporation | Full-bridge and half-bridge compatible driver timing schedule for direct drive backlight system |
US7755595B2 (en) | 2004-06-07 | 2010-07-13 | Microsemi Corporation | Dual-slope brightness control for transflective displays |
WO2010106375A3 (en) * | 2009-03-19 | 2010-12-02 | Juice Technology Limited | Electrical system using high frequency ac and having inductively connected loads, and related power supplies and luminaires |
US7952298B2 (en) | 2003-09-09 | 2011-05-31 | Microsemi Corporation | Split phase inverters for CCFL backlight system |
US7977888B2 (en) | 2003-10-06 | 2011-07-12 | Microsemi Corporation | Direct coupled balancer drive for floating lamp structure |
US8093839B2 (en) | 2008-11-20 | 2012-01-10 | Microsemi Corporation | Method and apparatus for driving CCFL at low burst duty cycle rates |
US8223117B2 (en) | 2004-02-09 | 2012-07-17 | Microsemi Corporation | Method and apparatus to control display brightness with ambient light correction |
US8358082B2 (en) | 2006-07-06 | 2013-01-22 | Microsemi Corporation | Striking and open lamp regulation for CCFL controller |
GB2497428A (en) * | 2011-12-06 | 2013-06-12 | Isotera Ltd | Two-part ferrite core power coupling and distribution arrangements |
US8598795B2 (en) | 2011-05-03 | 2013-12-03 | Microsemi Corporation | High efficiency LED driving method |
US8754581B2 (en) | 2011-05-03 | 2014-06-17 | Microsemi Corporation | High efficiency LED driving method for odd number of LED strings |
US8779686B2 (en) | 2010-10-24 | 2014-07-15 | Microsemi Corporation | Synchronous regulation for LED string driver |
US9030119B2 (en) | 2010-07-19 | 2015-05-12 | Microsemi Corporation | LED string driver arrangement with non-dissipative current balancer |
US9614452B2 (en) | 2010-10-24 | 2017-04-04 | Microsemi Corporation | LED driving arrangement with reduced current spike |
GB2547452A (en) * | 2016-02-18 | 2017-08-23 | Inductronics Tech Ltd | An inductive coupling device and system |
NL2016810B1 (en) * | 2016-05-23 | 2017-11-30 | Optimos Apto B V | A method, a controller and a network |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2056680A1 (en) * | 1970-11-18 | 1972-05-25 | Pfister K | Infinitely variable transformer |
EP0264135A2 (en) * | 1986-10-17 | 1988-04-20 | Kabushiki Kaisha Toshiba | Power supply system for discharge load |
-
1992
- 1992-09-14 EP EP92115671A patent/EP0587923A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2056680A1 (en) * | 1970-11-18 | 1972-05-25 | Pfister K | Infinitely variable transformer |
EP0264135A2 (en) * | 1986-10-17 | 1988-04-20 | Kabushiki Kaisha Toshiba | Power supply system for discharge load |
Cited By (46)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0880873A1 (en) * | 1995-10-24 | 1998-12-02 | Auckland UniServices Limited | Inductively powered lighting |
EP0880873A4 (en) * | 1995-10-24 | 1999-12-01 | Auckland Uniservices Ltd | Inductively powered lighting |
WO1998033256A1 (en) * | 1997-01-28 | 1998-07-30 | Tunewell Technology Limited | An a.c. current distribution system |
US6344699B1 (en) | 1997-01-28 | 2002-02-05 | Tunewell Technology, Ltd | A.C. current distribution system |
WO2002035489A1 (en) * | 2000-10-23 | 2002-05-02 | Augier S.A. | Energy-saving light marking device with low power consumption |
US6828738B2 (en) | 2000-10-23 | 2004-12-07 | Augier S.A. | Energy-saving light marking device with low power consumption |
FR2815809A1 (en) * | 2000-10-23 | 2002-04-26 | Augier S A | Warning lamp system with low energy consumption, uses main transformer driven by current source supplying series connected lamp units, each lamp unit having fluorescent tube supplied through transformer |
WO2002035891A2 (en) * | 2000-10-25 | 2002-05-02 | Raymarine Limited | Fluorescent lamp driver circuit |
WO2002035891A3 (en) * | 2000-10-25 | 2002-08-08 | Raymarine Ltd | Fluorescent lamp driver circuit |
US6879114B2 (en) | 2000-10-25 | 2005-04-12 | Raymarine Limited | Fluorescent lamp driver circuit |
EP1397028A1 (en) * | 2002-09-06 | 2004-03-10 | Minebea Co., Ltd. | Ballast for a plurality of discharge lamps |
US6784627B2 (en) | 2002-09-06 | 2004-08-31 | Minebea Co., Ltd. | Discharge lamp lighting device to light a plurality of discharge lamps |
US7781916B2 (en) | 2003-05-26 | 2010-08-24 | Auckland Uniservices Limited | Parallel-tuned pick-up system with multiple voltage outputs |
WO2004105207A1 (en) * | 2003-05-26 | 2004-12-02 | Auckland Uniservices Limited | Parallel-tuned pick-up system with multiple voltage outputs |
US7952298B2 (en) | 2003-09-09 | 2011-05-31 | Microsemi Corporation | Split phase inverters for CCFL backlight system |
EP1671521A2 (en) * | 2003-10-06 | 2006-06-21 | Microsemi Corporation | A current sharing scheme and device for multiple ccf lamp operation |
EP1671521A4 (en) * | 2003-10-06 | 2007-06-13 | Microsemi Corp | A current sharing scheme and device for multiple ccf lamp operation |
US8222836B2 (en) | 2003-10-06 | 2012-07-17 | Microsemi Corporation | Balancing transformers for multi-lamp operation |
US8008867B2 (en) | 2003-10-06 | 2011-08-30 | Microsemi Corporation | Arrangement suitable for driving floating CCFL based backlight |
US7990072B2 (en) | 2003-10-06 | 2011-08-02 | Microsemi Corporation | Balancing arrangement with reduced amount of balancing transformers |
US7977888B2 (en) | 2003-10-06 | 2011-07-12 | Microsemi Corporation | Direct coupled balancer drive for floating lamp structure |
US7932683B2 (en) | 2003-10-06 | 2011-04-26 | Microsemi Corporation | Balancing transformers for multi-lamp operation |
US8223117B2 (en) | 2004-02-09 | 2012-07-17 | Microsemi Corporation | Method and apparatus to control display brightness with ambient light correction |
EP1730617A4 (en) * | 2004-03-12 | 2010-10-06 | Juno Mfg Inc | Constant current class 3 lighting system |
EP1730617A2 (en) * | 2004-03-12 | 2006-12-13 | Juno Manufacturing, Inc. | Constant current class 3 lighting system |
US7646152B2 (en) | 2004-04-01 | 2010-01-12 | Microsemi Corporation | Full-bridge and half-bridge compatible driver timing schedule for direct drive backlight system |
US7965046B2 (en) | 2004-04-01 | 2011-06-21 | Microsemi Corporation | Full-bridge and half-bridge compatible driver timing schedule for direct drive backlight system |
US7755595B2 (en) | 2004-06-07 | 2010-07-13 | Microsemi Corporation | Dual-slope brightness control for transflective displays |
US8358082B2 (en) | 2006-07-06 | 2013-01-22 | Microsemi Corporation | Striking and open lamp regulation for CCFL controller |
US8093839B2 (en) | 2008-11-20 | 2012-01-10 | Microsemi Corporation | Method and apparatus for driving CCFL at low burst duty cycle rates |
WO2010106375A3 (en) * | 2009-03-19 | 2010-12-02 | Juice Technology Limited | Electrical system using high frequency ac and having inductively connected loads, and related power supplies and luminaires |
US9107259B2 (en) | 2009-03-19 | 2015-08-11 | Isotera Limited | Electrical system using high frequency AC and having inductively connected loads, and related power supplies and luminaires |
US9030119B2 (en) | 2010-07-19 | 2015-05-12 | Microsemi Corporation | LED string driver arrangement with non-dissipative current balancer |
US9614452B2 (en) | 2010-10-24 | 2017-04-04 | Microsemi Corporation | LED driving arrangement with reduced current spike |
US8779686B2 (en) | 2010-10-24 | 2014-07-15 | Microsemi Corporation | Synchronous regulation for LED string driver |
US8754581B2 (en) | 2011-05-03 | 2014-06-17 | Microsemi Corporation | High efficiency LED driving method for odd number of LED strings |
US8598795B2 (en) | 2011-05-03 | 2013-12-03 | Microsemi Corporation | High efficiency LED driving method |
USRE46502E1 (en) | 2011-05-03 | 2017-08-01 | Microsemi Corporation | High efficiency LED driving method |
GB2497428B (en) * | 2011-12-06 | 2014-09-24 | Isotera Ltd | A coupler for use in a power distribution system |
GB2497428A (en) * | 2011-12-06 | 2013-06-12 | Isotera Ltd | Two-part ferrite core power coupling and distribution arrangements |
US10002702B2 (en) | 2011-12-06 | 2018-06-19 | Greengage Lighting Limited | Coupler for use in a power distribution system |
GB2547452A (en) * | 2016-02-18 | 2017-08-23 | Inductronics Tech Ltd | An inductive coupling device and system |
WO2017141224A1 (en) * | 2016-02-18 | 2017-08-24 | Inductronics Technology Ltd | An inductive coupling device and system |
GB2547452B (en) * | 2016-02-18 | 2019-06-12 | Inductronics Tech Limited | An inductive coupling device and system |
NL2016810B1 (en) * | 2016-05-23 | 2017-11-30 | Optimos Apto B V | A method, a controller and a network |
WO2017204629A1 (en) * | 2016-05-23 | 2017-11-30 | Optimos Apto B.V. | A method, a controller and a network |
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